Hereditary
Defects Advice - Progressive Retinal Atrophy (P.R.A.)
Centralised
Progressive Retinal
Atrophy (CPRA) is a serious condition which can lead to blindness in
Affected
dogs.
The disease
is caused by the
inability of some cells in the eye to produce enzymes which break down
waste
materials (most commonly, lipopigments)-these then accumulate on the
retina of
the eye. The cells in the eye which are sensitive to light then
degenerate,
causing partial or total blindness. It
can be detected in dogs as young as 12 months old, although most
Affected dogs
have been at least 18 months of age when they have been diagnosed.
The
mode of
inheritance
for this disease is
not known,
and it is thought that nutrition (particularly availability of Vitamin
E) also
plays a significant role.
As a
consequence of BVA/KC/ISDS eye testing schemes (and possibly better
nutrition),
the incidence of CPRA is now noted as being less than 0.25% in Border
Collies.
Dogs can be tested for CPRA whenever
they have a routine eye exam – for details and costs see the
CEA
section.
As yet
there is no genetic test
available for
CPRA.
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